This list was designed to show the last date of 80 degrees in the fall and the first date of 80 degrees in the spring, such that the difference between the two would be the number of days between occurrences of 80 degrees, not the number of calendar days without 80 degrees. The number of days shown is the duration from when the mercury fell below 80 degrees until it rose to 80 degrees again. This is the same concept used for growing season, which is measured from the last freeze in spring to the first freeze in the fall. It is distinctly different from a streak of 100-degree days, for example, which is the number of calendar days such an event is recorded.